This invention relates generally to door frames containing locks of the type commonly used in prisons and, more particularly, to mechanisms and methods for mounting such locks in the door frames.
In prisons and other detention facilities, high security doors are commonly used to lock prisoners in their cells and to secure passageways through which the prisoners may be transported. These doors typically utilize an electromechanical lock of the type which can be remotely locked and unlocked, such as by a guard positioned in a control room sending an electronic signal to the lock to cause extension or retraction of a latch bolt. The locks also contain a keyed cylinder which allows the latch bolt to be manually extended or retracted by a guard with a key, such as in the event of a power outage which prevents the locks from being controlled by the electronic signal.
In many installations, the electromechanical locks of the type described above are mounted in the door frame, rather than the door itself, to simplify routing of the electrical cable to the lock. These door frames are typically fabricated from heavy gauge metal and contain a hollow core which is filled with concrete during installation of the frame in the concrete or block wall. The frame also contains a lock pocket in which the lock is removably mounted. A cover plate is then secured over the lock using special security screws to block access to the lock pocket and installed lock.
In order to permit proper installation and operation of the locks described above, the mounting studs and the cutouts for the latch bolt, a latching roller and the cylinder must be precisely located in the lock pocket and cover plate. Because the location of the mounting studs, latches and cylinders may vary from one lock to another, particularly when the locks are made by different manufacturers, conventional lock pockets and cover plates are specially made for the particular type of lock which is to be installed in the lock pocket. Moreover, once a conventional lock pocket has been fabricated for a specific type of lock, it may be problematic to reconfigure the lock pocket to accept another type of lock, particularly if the mounting studs and latch cutouts must be repositioned. As a result, a need exists for a door frame which can be readily modified to accept different lock configurations so that the installed lock can be easily replaced with a different brand of lock, such as if a problem develops with the installed lock.
The inability of conventional door frames to readily adapt to different lock configurations generally means that the door frames are not fabricated during the construction of new prisons or detention facilities until the specific brand of lock has been specified. If the lock specification is not established early enough in the design process, the time required to fabricate, deliver and install the door frames can cause significant and costly construction delays. As a result, a need has developed for a door frame which can be readily adapted to accept different brands of locks so that the door frames can be fabricated even though the lock specifications have not been established.
In one aspect, the present invention is directed to a door and frame assembly comprising a hinge jamb and a latch jamb extending in spaced apart and generally parallel relationship, a head jamb extending between the hinge and latch jambs at an upper end thereof. The hinge, latch and head jambs define an opening in which a door is positioned. The door is mounted by hinges to the hinge jamb and is moveable between a closed position within the opening and an open position swung away from the opening. The latch jamb comprises spaced apart first and second faces and a side member extending between the faces at said opening. A cutout in the first face and the side member of the latch jamb forms a pocket in which a lock having a cylinder and latch bolt is mounted. A lock cover plate removably covers the cutout in the first face and a latch cover plate carried by and extending from said lock cover plate removably covers the cutout in the side member of the latch jamb. A latch cutout is positioned in the latch cover plate to permit the latch bolt to be extended through the latch cover plate and a cylinder cutout is positioned in the lock cover plate to permit access to the cylinder. An array of mounting apertures are formed in the second face of the latch jamb and fasteners extend through mounting holes and removably mounting said lock within said pocket. An array of indicia are formed in the second face of the latch jamb and are positioned to designate the locations of mounting apertures for a replacement lock positioned within the pocket and having a different mounting configuration.
In another aspect, the invention is directed to a method of assembling and installing the door and frame assembly within an opening in a wall. The method comprises the steps of: (a) providing the door and frame assembly, (b) securing the door and frame assembly to the wall at said wall opening, (c) removably mounting, within the pocket, a lock having either a first or second mounting configuration by extending fasteners through the mounting apertures corresponding to the mounting configuration, and (d) removably securing, to the latch jamb, a lock cover plate sized for covering the cutout in the first face and a latch cover plate carried by the lock cover plate and sized to cover the cutout in the side member, the lock cover plate having a cylinder cutout to permit access to the lock cylinder and the latch cover plate having a latch cutout positioned to permit the latch bolt to extend through the latch cover plate.
One advantage of the door frame of the present invention is the lock mount can be readily modified to accept different lock configurations so that the door frame can be fabricated for use in prison construction even though the lock specifications have yet to be established.
Another advantage of the door frame is the lock mount can be readily modified to accept different lock configurations so that the installed lock can be replaced with a lock having a different configuration, such as if problems should develop with the lock initially installed.